Refrigerant evaporator device



Aug. 27, 1935. D. P. HEATH REFRIGERANT'EVAPORA'ITOR DEVICE Original Filed April 23, 1932 FIG-l I2VENTO29E Patented Aug. 27, 1935- UNITED STATES REFBIGEBANT svaroaa'roa DEVICE Delos r. Heath, Detroit, Mich.

Application April 23, 1 32, Serial No. 607,117- Renewed J 13, 1934 7 Claims. '(CL' 6%-126) The invention relates to a sheet metal evaporator for mechanical refrigeration In general and particularly to evaporators employed to freeze water and cool the airof the food compartments.

5 This evaporator is placed in the refrigerant circuit of 'a closed cycle refrigerating machine that produces its cooling effect by vaporizingliquid refrigerant contained within the evaporator walls. v

The invention has for its object to provide methods and structure for astronger gas and liquid .chamber. Another object is to provide a more compact evaporator requiring less volume within the food chamber. I l a Another object is to provide a simple and improved method of forming and sealing the liduld I distributing walls of the evaporator which enclose the ice freezing chamber.

The invention provides an evaporator formed of two thin sheets of metal. One sheet-provides the side walls of a cylindricalgas and liquid header and the outer casing of the liquid distributing chamber about the ice freezing compartment. The other sheet, which is fused to the outer casing, forms the inner casing of the liquid refrigerant distributing chamber and the walls of the ice freezing chamber.

In the drawing:

Figurel is a part plan view of the outer casin after the first stamping operation.

Figure 2 is a section in elevation on the line 8-3 of Figure 1,

Figure 3 is a part plan view of the casing of Figure 1 after forming and expanding the gas-liquidheader portion. a

Figure 4,isa front elevation in section on the line l- -I of Figure 3, showing the forming laws I and the expanding mandrel.

Figure 5 is a front'elevation line 2-2 of Figure 3.

Figure 6 is a perspective of a conventional header ring and float valve platdassembly.

Figure 7 is a side elevation end. v

Figure 8 is apart plan view of the inner casing after the first sta p n Operation.

in section on the Figure 9 is a front elevation construction in section on the line 4-4, Figure 8. I

Figure 10 is a perspective of the assembled "outer and 'inner casings fused together; with ice trays shown .in the freezing chamber.

Figure 11 is a part plan view of a modification of the outer casing shown in Figure 3.

of a dished header Figure 12 is a front elevation in section on line 5-5 Figure 11. Figure 13 is a part elevation of the evaporator ln section showing a full assembly with the liquid inlet and outlet through the headerside wall.

Rectangular blanks of light gauge sheet metal are formed by stamping or rolling with the em bossing or corrugations as shown in Figures 1 and 8. Sheet I, Figure 1, has an intermediate portion formed into the large transverse header or 10 I manifold wall, 6; This header wall has an arouate portion and flat portions extending therefrom above the center of the circle of the arcuate-portion. The ends of the sheet I'extend on either side of the header 6 with a plurality of emhoss 15 ings 2, formed in the sheet. These embossings or corrugations may connect with the header 2, but for reasons hereafter given, I prefer to stop the embossing short of the header. At the termination of the embossings 2 nearthe ends of the sheet I, are transverse headers or manifolds I, which connect the embossings at their ends.

After the first stamping operation, the header 0 of the casing I is slid under the horizontal mandrel I9, and the press block 22, Figure 4. The forming Jaws I6 and I1 are rotated toward each other on shaft I2 to form or shape the header 6 into a cylindrical wall of circular section, having opposite portions of sheet I contacting each other at 23 adjacent the mouth of the I header chamber 8. The pointed end of the mandrel 2|, is then pressed downward between opposite portions of sheet I at 22 and without rupturing the sheet metal the passageways I! are formed at points in line with the em or 5 corrugations 2. To provide space for the mandrel after it passes the contacting edges of sheet I at 23 andspace for the deformed sheet metal at the passageways l3, I-have provided drilled holes or a slotted recess 20, in the mandrel 2|.

After these passageways it have been established the contacting portions of sheet-latv 22 are fused together by projection or flash welding, electric arc, flame welding, or by copper brazing .in a hydrogen atmosphere. I have also shown in Figures 11 and 12 a modification of this method of fixing the intermediate portions of sheet I together to form a header, having cylindrical side walls. In Figure 11, the sheet I is formed together by the jaws I6 and I! but the adjacent 60 folds of the sheet extending from the header I do not contact. Welds are formed between the F portions of sheet I at 22, in such a way that spaces remain in line with the embossing orcorrugations 2,1so that the bubbles of gaseous reheader 8, by way of passages 33 between contiguousor spaced apart portions 14 and I5. The

- mandrel 2| is not used in this method of assembly.

The sheet I, with its welded header portion and sheet 8 are then shaped to provide the top wall 28, the side walls 28. and the bottom walls 21, Figure 10; and also the welding flanges 28. -This may be done either before or after fusing the sheets I and 8 together. In assembling the sheets 'I and 8 intermediate flat portions 3 and I0, and. flat peripheral portions 1 and I2 contact. The corrugations or embossings 2, 9, ahd ll register to form connecting passageways with each other and with the passages l3 or 33 and the header 6. The fusing of 3 to In strengthens the flat portions of the evaporator wall and permits it to maintain its shape under high internal pressure. The fusing of the peripheral edges I and i2 seals the container at the sides and the fusing together of the four flanges 28. seals the bottom of the evaporator at 29.

Figure 10 shows the, two shells assembled without header end plates. I have found that it is practical to fuse sheets I and 8 together be-.

fore establishing the fused joint 24 of Figure 5 or the joint 32 of Figure 12.

type, I show a gas and liquid header side wall formed from portions of the two sheets, which are extended to enclose the freezing chamber. This construction necessitates fusing the sheets together adjacent the header at a considerable distance from the circular portion of the header because the fillets required in the die used in stamping the header, do not allow the sheets to contact close to the circular header. Extreme stresses are therefore set up on welds at the header and as the strain is not all in tension, these welds may be weakened or ruptured by torsional stress.

My invention provides the improved structure of gas and liquid header formed from the outer sheet only, thus requiring but one row of fused joints, and permitting welds to be placed under tension only. A very much stronger; evaporator header results from this arrangement. v

After the sheets i and 8 are assembled together. the header end discs may be fused at either end of the gas liquid header after the installation ofthe float mechanism shown in Figure 13. 'The float 37- in Figure I3 is ,pivoted to the bracket 38 which is permanently secured to. the header 8 or the header end-plate 35. This float and its lever operate the valve rod 48 which controls theinlet'of liquid refrigerant to maintain a levei'cf'liquid refrigerantand oil in the: header 8 at approximately the level shown by the dotted line in Figure 10.

:I have also assembled one of the end plates-38 in the header and the conventional ring 34 'carrying the float'valve plate 38 and its float 11,---However', the assembly of Figure 13 which operates through the sidewall of the header Bpermits servicing the valve exterior to the header.

Ice tray 30 is formed with a lip or flange 38 extending upwardly at an angle that conforms with the upper surface of the shelf corrugation ll ofthe shell 8. I have found that an angle of approximately 30 degrees provides the least difliculty in manufacturing and promotes rapid ice freezing in the trays. 5

Numeral 4 is an ice tray stop embossed in the sheet 8 at right angles to the ice tray quick freezing shelf I i. This stop 4 may extend downwardly to connect with other tray shelves in evaporators requiring more trays than shown in Figure 10.

shelf or it may contact the bottom 21 of the freezing compartment. In either case improved ice freezing results because liquid refrigerant contacts the metallic support of the ice tray.

In operation the liquid refrigerant is admitted through the evaporator by a float valve of either the high or low pressure type, and 9. capillary tube or some other means operating in the refrigerant circuit to insure condenser-v evaporator pressure differential.

The embossed portions of sheets I and 8 allow channels of liquid refrigerant to contact and cool a large area of the l side's of the freezing chamber. The header six usually has approximately half its volume filled with liquid refrigerant and oil. while the remainder of the header contains gaseous refrigerant. When the system is in operation this gas is withdrawn from the header and the liquid refrigerant boils and removes the heat from the food chamber and the ice travs which it receives by conduction through the evaporator walls. 7

As the volume of the header 8 is very large compared to the'summatidn of .thevolumes of thefeatures reduce the maintenance expense of the refrigerating system.

Iclaim:

1. A heat absorbing unit for refrigerating apparatus comprising a metallic memberhaving sheet-like portions secured together, a part of one of the-sheet-like portions extending away from the other, said extending part being in the form of a loop having a mouth, the-metal forming the sides'of the mouth being' fastened toge'ther, said other sheet-like portion extending directly across the moiith of the looped portion and being fastened tothe looped sheet-like portion on opposite sides of the mouth, said sheetlike portions being formed to provide refrigerant passages therebetween' connecting with the looped portion. 1

2. A heat absorbing unit for refrigerating apparatus comprising a metallic member having sheet-like portions secured together, a part of gether, said other sheet-like portion extending directly across the mouthof the looped portion and being fastened to the looped sheet-like porsaid sheet-like portions having a part spaced,

tion on opposite sides of the mouth, said sheetlike portions being formed toproviderefrigerant passages therebetween, said mouth having refrigerantpassages formed therein between the fastened portions thereof connecting with the re frigerant passages between the sheet-like portions.

' 3. A heat absorbing unit for refrigerating apparatus including a metallic member having a first and a, second sheet-like portion secured together, a part of the first sheet-like portion extending away from the second sheet-like portion in the form of a loop having a mouth, the metal forming the sides of the mouth being fastened together, the second sheet-like portion extending directly across the mouth of the looped portion and being fastened to the first sheet-like portion on opposite sides of the mouth, said sheet-like portions having refrigerant passages therebetween, said second sheet-like portion being grooved across the mouth of the looped portionto provide communication between the refrigerant passages and the looped portion.

4. A heat absorbing unit for refrigerating apparatus including a metallic member having a firstand a second sheet-like'portion secured together, a part of the first sheet-like portion extending away from the second sheet-like portion in the form of a loop having a mouth, the metal I forming the sides of the mouth being fastened together, the secondsheet-like portion extending directly across the mouth of the looped portion and being fastened to the first sheet-like portion on opposite sides of the mouth, said first sheetlike portion having grooves therein terminating short of the looped portion thereof, said grooves forming refrigerant passages between the sheetlike portions, said second sheet-like portion having grooves therein extending from the mouth of the looped portion of the first sheet to the grooves of the first sheet to connect the'refrigerant passages to the looped portion. 5. A' heat absorbing unit for refrigerating apparatus including a metal member having a first and a second sheet-like portion secured together,

apart to form a chamber, said first sheet-like portion having grooves terminating short of the .chamber, said grooves forming refrigerant passages between the sheet-like portions, said second sheet-like portion having grooves which extend from thechamber to meet the grooves in the first sheet-like portion for connecting the refrigerant passages to the chamber.

6. A heat absorbing unit for refrigerating apparatus including a metallic member having sheet-like portions secured together, a part of one of the sheet-like portionsextending away from the other to form a substantially cylindrical wall of an elongated chamber having a narrow mouth, said other sheet-like portion extending continuously across the mouth of the chamber and being corrugated throughout substantially the greaterpart of the width of the mouth in a direction transverse to the chamber and fastened to the opposite sides of the mouth for structural strength, and said sheet-like portions being formed to provide refrigerant passages therebetween'communicating with said chamber.

7. A heat absorbing unit for refrigerating apparatus including a metallic member having sheet-like portions secured together, a part of one of the sheet-like portions extending away from the other to form a substantially cylindrical wall of an elongated chamber and having other parts-thereof extending from the chamber wall, said other extending parts of the said one of the sheet-like portions having parts thereof spaced 

